[Fix] DeepSeek Flash cannot read attached images

packages/types/src/__tests__/deepseek-v4-pro.test.ts

@@ -10,12 +10,18 @@ describe("DeepSeek V4 Pro 0813 provider catalogs", () => {
 		expect(model?.contextWindow).toBeGreaterThanOrEqual(1_000_000)
 	})
 
-	it("uses peak first-party pricing and unchanged OpenCode Go pricing", () => {
+	it("uses current peak first-party pricing and unchanged OpenCode Go pricing", () => {
+		expect(deepSeekModels["deepseek-flash"]).toMatchObject({
+			supportsImages: true,
+			outputPrice: 1.2,
+			cacheWritesPrice: 0.3,
+			cacheReadsPrice: 0.006,
+		})
 		expect(deepSeekModels["deepseek-v4-flash"]).toMatchObject({
-			supportsImages: false,
-			outputPrice: 1.32,
-			cacheWritesPrice: 0.44,
-			cacheReadsPrice: 0.014,
+			supportsImages: true,
+			outputPrice: 1.2,
+			cacheWritesPrice: 0.3,
+			cacheReadsPrice: 0.006,
 		})
 		expect(deepSeekModels["deepseek-v4-pro"].supportsImages).toBe(false)
 		expect(deepSeekModels["deepseek-v4-pro"]).toMatchObject({
@@ -42,6 +48,10 @@ describe("DeepSeek V4 Pro 0813 provider catalogs", () => {
 		expect(model.supportsPromptCache).toBe(true)
 		expect(model.contextWindow).toBeGreaterThanOrEqual(1_000_000)
 		expect(model.supportsReasoningEffort).toEqual(["disable", "low", "high", "max"])
+		expect(model).toMatchObject({ outputPrice: 1.2, cacheWritesPrice: 0.3, cacheReadsPrice: 0.006 })
+		expect(model.description).toContain("Legacy model name")
+		expect(model).not.toHaveProperty("supportsTemperature")
+		expect(model).not.toHaveProperty("defaultTemperature")
 	})
 
 	// Self-hosted providers retain separate IDs for the preview weights and 0813 checkpoint.

packages/types/src/providers/deepseek.ts

@@ -6,23 +6,38 @@ import type { ModelInfo } from "../model.js"
 // continuation within the same turn. See: https://api-docs.deepseek.com/guides/thinking_mode
 export type DeepSeekModelId = keyof typeof deepSeekModels
 
-export const deepSeekDefaultModelId: DeepSeekModelId = "deepseek-v4-flash"
+export const deepSeekDefaultModelId: DeepSeekModelId = "deepseek-flash"
 
 export const deepSeekModels = {
+	"deepseek-flash": {
+		maxTokens: 384_000,
+		contextWindow: 1_000_000,
+		supportsImages: true,
+		supportsPromptCache: true,
+		supportsReasoningEffort: ["disable", "low", "high", "max"], // Updated 2026-09-10
+		preserveReasoning: true,
+		reasoningEffort: "high",
+		inputPrice: 0, // the inputs are priced as cache read/write, so `inputPrice` should be 0
+		// Static estimates use peak rates; off-peak rates are 50% lower. Effective 2026-09-10.
+		outputPrice: 1.2,
+		cacheWritesPrice: 0.3,
+		cacheReadsPrice: 0.006,
+		description: `DeepSeek-V4.1-Flash is DeepSeek's fast multimodal model with image understanding. It supports thinking and non-thinking modes, JSON output, tool calls, chat prefix completion (beta), and FIM completion (beta) in non-thinking mode.`,
+	},
 	"deepseek-v4-flash": {
 		maxTokens: 384_000,
 		contextWindow: 1_000_000,
-		supportsImages: false,
+		supportsImages: true,
 		supportsPromptCache: true,
 		supportsReasoningEffort: ["disable", "low", "high", "max"], // Updated 2026-08-13
 		preserveReasoning: true,
 		reasoningEffort: "high",
 		inputPrice: 0, // the inputs are priced as cache read/write, so `inputPrice` should be 0
-		// Static estimates use peak rates; off-peak rates are 50% lower. Effective 2026-08-16.
-		outputPrice: 1.32,
-		cacheWritesPrice: 0.44,
-		cacheReadsPrice: 0.014,
-		description: `DeepSeek-V4-Flash is DeepSeek's fast, cost-efficient V4 model. It supports thinking and non-thinking modes, JSON output, tool calls, chat prefix completion (beta), and FIM completion (beta) in non-thinking mode.`,
+		// This retired ID is billed as the current Flash model.
+		outputPrice: 1.2,
+		cacheWritesPrice: 0.3,
+		cacheReadsPrice: 0.006,
+		description: `Legacy model name routed to the latest DeepSeek Flash model, which supports image input. Use deepseek-flash for new configurations.`,
 	},
 	"deepseek-v4-pro": {
 		displayName: "DeepSeek V4 Pro 0813",
@@ -49,14 +64,12 @@ export const deepSeekModels = {
 		supportsReasoningEffort: ["disable", "low", "high", "max"], // Updated 2026-08-13
 		preserveReasoning: true,
 		reasoningEffort: "high",
-		supportsTemperature: true,
-		defaultTemperature: 1.0,
 		inputPrice: 0, // the inputs are priced as cache read/write, so `inputPrice` should be 0
-		// Static estimates use peak rates; off-peak rates are 50% lower.
-		outputPrice: 1.32,
-		cacheWritesPrice: 0.44,
-		cacheReadsPrice: 0.014,
-		description: `DeepSeek-V4-Flash-Vision-Exp is DeepSeek's experimental multimodal V4 Flash model with image understanding. It supports thinking and non-thinking modes, JSON output, tool calls, chat prefix completion (beta), and image input through Chat Completions, Responses, and Anthropic-compatible APIs.`,
+		// This retired ID is billed as the current Flash model.
+		outputPrice: 1.2,
+		cacheWritesPrice: 0.3,
+		cacheReadsPrice: 0.006,
+		description: `Legacy model name routed to the latest DeepSeek Flash model, which supports image input. Use deepseek-flash for new configurations.`,
 	},
 } as const satisfies Record<string, ModelInfo>
 

src/api/providers/__tests__/deepseek.spec.ts

@@ -240,22 +240,22 @@ describe("DeepSeekHandler", () => {
 			expect(model.info).toBeDefined()
 			expect(model.info.maxTokens).toBe(384_000)
 			expect(model.info.contextWindow).toBe(1_000_000)
-			expect(model.info.supportsImages).toBe(false)
+			expect(model.info.supportsImages).toBe(true)
 			expect(model.info.supportsPromptCache).toBe(true) // Should be true now
 			expect((model.info as ModelInfo).preserveReasoning).toBe(true)
 		})
 
-		it("should use deepseek-v4-flash as the default model ID for new configs", () => {
+		it("should use deepseek-flash as the default model ID for new configs", () => {
 			const handlerWithoutModel = new DeepSeekHandler({
 				...mockOptions,
 				apiModelId: undefined,
 			})
 			const model = handlerWithoutModel.getModel()
 			expect(model.id).toBe(deepSeekDefaultModelId)
-			expect(model.id).toBe("deepseek-v4-flash")
+			expect(model.id).toBe("deepseek-flash")
 			expect(model.info.maxTokens).toBe(384_000)
 			expect(model.info.contextWindow).toBe(1_000_000)
-			expect(model.info.supportsImages).toBe(false)
+			expect(model.info.supportsImages).toBe(true)
 			expect((model.info as ModelInfo).supportsReasoningEffort).toContain("max")
 		})
 
@@ -290,7 +290,6 @@ describe("DeepSeekHandler", () => {
 				supportsPromptCache: true,
 				preserveReasoning: true,
 				reasoningEffort: "high",
-				defaultTemperature: 1.0,
 			})
 		})
 
@@ -369,41 +368,61 @@ describe("DeepSeekHandler", () => {
 			expect(textChunks[0].text).toBe("Test response")
 		})
 
-		it("should send images and V4 thinking controls to deepseek-v4-flash-vision-exp", async () => {
+		it.each(["deepseek-flash", "deepseek-v4-flash", "deepseek-v4-flash-vision-exp"] as const)(
+			"should send images and thinking controls to %s",
+			async (modelId) => {
+				const visionHandler = new DeepSeekHandler({
+					...mockOptions,
+					apiModelId: modelId,
+				})
+				const visionMessages: Anthropic.Messages.MessageParam[] = [
+					{
+						role: "user",
+						content: [
+							{ type: "text", text: "Describe this image." },
+							{
+								type: "image",
+								source: { type: "base64", media_type: "image/png", data: "image-data" },
+							},
+						],
+					},
+				]
+
+				await collectStream(visionHandler.createMessage(systemPrompt, visionMessages))
+
+				const callArgs = mockCreate.mock.calls[0][0]
+				expect(callArgs).toMatchObject({
+					model: modelId,
+					thinking: { type: "enabled" },
+					reasoning_effort: "high",
+					max_completion_tokens: 200_000,
+				})
+				expect(callArgs.temperature).toBeUndefined()
+				expect(callArgs.messages).toContainEqual({
+					role: "user",
+					content: expect.arrayContaining([
+						{ type: "text", text: expect.stringContaining("Describe this image.") },
+						{ type: "image_url", image_url: { url: "data:image/png;base64,image-data" } },
+					]),
+				})
+			},
+		)
+
+		it("should use the provider default temperature when reasoning is disabled for the vision alias", async () => {
 			const visionHandler = new DeepSeekHandler({
 				...mockOptions,
 				apiModelId: "deepseek-v4-flash-vision-exp",
+				enableReasoningEffort: false,
 			})
-			const visionMessages: Anthropic.Messages.MessageParam[] = [
-				{
-					role: "user",
-					content: [
-						{ type: "text", text: "Describe this image." },
-						{
-							type: "image",
-							source: { type: "base64", media_type: "image/png", data: "image-data" },
-						},
-					],
-				},
-			]
 
-			await collectStream(visionHandler.createMessage(systemPrompt, visionMessages))
+			await collectStream(visionHandler.createMessage(systemPrompt, messages))
 
-			const callArgs = mockCreate.mock.calls[0][0]
-			expect(callArgs).toMatchObject({
+			expect(mockCreate.mock.calls[0][0]).toMatchObject({
 				model: "deepseek-v4-flash-vision-exp",
-				thinking: { type: "enabled" },
-				reasoning_effort: "high",
-				max_completion_tokens: 200_000,
-			})
-			expect(callArgs.temperature).toBeUndefined()
-			expect(callArgs.messages).toContainEqual({
-				role: "user",
-				content: expect.arrayContaining([
-					{ type: "text", text: expect.stringContaining("Describe this image.") },
-					{ type: "image_url", image_url: { url: "data:image/png;base64,image-data" } },
-				]),
+				thinking: { type: "disabled" },
+				temperature: 0,
 			})
+			expect(mockCreate.mock.calls[0][0].reasoning_effort).toBeUndefined()
 		})
 
 		it("should include usage information", async () => {

src/api/providers/deepseek.ts

@@ -28,7 +28,12 @@
 	reasoning_effort?: "low" | "high" | "max"
 }
 
-const deepSeekV4ThinkingModels = new Set(["deepseek-v4-flash", "deepseek-v4-pro", "deepseek-v4-flash-vision-exp"])
+const deepSeekV4ThinkingModels = new Set([
+	"deepseek-flash",
+	"deepseek-v4-flash",
+	"deepseek-v4-pro",
+	"deepseek-v4-flash-vision-exp",
+])
 const supportsDeepSeekThinkingToggle = (modelId: string) => deepSeekV4ThinkingModels.has(modelId)
 
 // Only known V4 models and the legacy reasoner alias support DeepSeek's
@@ -49,6 +54,7 @@
 ): "low" | "high" | "max" | undefined => {
 	// still check the modelId so non-supported models won't produce reasoning efforts
 	switch (modelId) {
+		case "deepseek-flash":
 		case "deepseek-v4-flash":
 		case "deepseek-v4-pro":
 		case "deepseek-v4-flash-vision-exp":

src/api/providers/fetchers/__tests__/deepseek.spec.ts

@@ -29,11 +29,24 @@ describe("getDeepSeekModels", () => {
 		const models = await getDeepSeekModels("http://127.0.0.1:43123/v1", "mock-key")
 
 		expect(globalThis.fetch).toHaveBeenCalledWith("http://127.0.0.1:43123/models", expect.any(Object))
+		expect(models["deepseek-flash"]).toEqual(deepSeekModels["deepseek-flash"])
 		expect(models["deepseek-v4-flash"]).toEqual(deepSeekModels["deepseek-v4-flash"])
 		expect(models["deepseek-v4-pro"]).toEqual(deepSeekModels["deepseek-v4-pro"])
 		expect(models["deepseek-v4-flash-vision-exp"]).toEqual(deepSeekModels["deepseek-v4-flash-vision-exp"])
 	})
 
+	it("applies vision metadata to the canonical Flash model returned by DeepSeek", async () => {
+		globalThis.fetch = vi.fn().mockResolvedValue({
+			ok: true,
+			json: vi.fn().mockResolvedValue({ data: [{ id: "deepseek-flash" }] }),
+		}) as unknown as typeof fetch
+
+		const models = await getDeepSeekModels(undefined, "test-key")
+
+		expect(models["deepseek-flash"]).toEqual(deepSeekModels["deepseek-flash"])
+		expect(models["deepseek-flash"].supportsImages).toBe(true)
+	})
+
 	it("throws for 404 responses when fallback flag is not enabled", async () => {
 		delete process.env.E2E_MOCK_MODEL_LIST_FALLBACK